I'll save you guys the story and me complaining about it, but my computer got too hot today when I started playing the Final Fantasy XIV Beta. Needless to say, it almost touched 80 C according to CoreTemp.

ExoGeni wrote:Question is: With this heat sink weighing in at around 800 grams (roughly 1.75 lb). Will this bend or warp my motherboard over time?

No, it uses a sturdy bracket, and motherboard PCBs are more rigid and durable than you might imagine. Just make sure to carefully install it. Crushing the CPU during installation and/or dropping the heatsink onto the motherboard could cause fatal damage.

With a heat-sink that heavy, the over time may be an issue since sooner or later your PC will be subject to shock or vibe that will stress the mounted parts on the PCB, possibly to cracking. Mostly this is a risk if your PCB main board is mounted vertically. Otherwise that heat-sink would be best mounted on a horizontal PCB. That is if the heatsink does not have some sort of additional support other than the socket retention (which it appears not to). Supporting the heatsink to the case wont help all that much either. Ideally you would have standoffs mounting the heatsink to the case through the PCB on the backside of the CPU to firmly attach the heatsink/CPU/PCB/Case together.

Personally I wouldn't trust it, and if you need that much cooling, use a water block setup instead. Otherwise if your CPU is running that hot stock, you may want to instead use Arctic Silver, re-seat the heat-sink, and check your fan speed on what you have now.

ExoGeni wrote:Question is: With this heat sink weighing in at around 800 grams (roughly 1.75 lb). Will this bend or warp my motherboard over time?

No, it uses a sturdy bracket, and motherboard PCBs are more rigid and durable than you might imagine. Just make sure to carefully install it. Crushing the CPU during installation and/or dropping the heatsink onto the motherboard could cause fatal damage.

You may be surprised how wimpy a hot PCB really is. Cold, sure, strong as hell, but at 60C+ they start to get softer. Mostly you have to be careful of the shock and vibe aspect. Drop the case a little, give it a kick, place it on a subwoofer...

I've been running my system with a 700 gram cooler for about two years, with no signs of cracking or bending or warping. My Gigabyte motherboard does have a thick layer of copper in it, but I've never heard of a securely-mounted tower heat sink warping or cracking a motherboard. If your desktop PC is often subject to serious bumps or shocks, then you're doing something wrong. I would be more concerned about fitting the massive thing into your case.

If you are really worried, there are plenty of lighter-weight heatsinks that should provide more than adequate cooling. Can you tell us more about your current cooling system?

If you have a subwoofer capable of breaking a motherboard with a securely-mounted heatsink on it, you must have that speaker system from the original Back to the Future.

Mostly when you find a mode of resonance... never a good thing. Sure you may not see any damage, you probably wont. Chances are slim that you will get damage, but I am simply saying it is not something I am comfortable with. Plenty of experience designing large PCBs in aircraft and commercial use, and I know their limitations.

liquidsquid wrote:Plenty of experience designing large PCBs in aircraft and commercial use, and I know their limitations.

I don't doubt your experience with PCBs, but when you compare a typical desktop PC environment to aircraft and commercial use, I question whether you're being overly cautious to the point of extreme.

But yeah, I agree that bolting a 1.5lb block of metal to an expensive motherboard can certainly make many people concerned. Therefore, OP, if you'd like suggestions for a heatsink that is both cheaper and lighter weight, let us Gerbils know, and I am sure we can suggest something good.

Captain Ned wrote:I've had a Thermalright Ultra 120 Extreme, weighing 790 grams, bolted to my Asus IP35 Pro since July 2007 under 24/7/365 conditions (including heavy gaming) and have not had the slightest issue.

I also have had the TRUE for a number of years and have not had any issues. So far it has survived driving it across town and back roughly every other month and a couple earthquakes (magnitude roughly 3-4). A good bolt-through backplate mounting system should do the trick; I wouldn't trust push-down clips (like the stock coolers), though.

I don't think there's any need to worry. As others have noted, PCBs are quite sturdy (at least in the environment typically encountered inside a PC), and the heatsink mounts to a bracket that is bolted through the motherboard.

Most of the heavy heatsink horror stories are from back in the day when the heatsink clipped to tabs on the CPU socket (instead of bolting through the PCB), and/or the CPU die was completely exposed (no metal cap/heatspreader). Busted CPU sockets and crushed CPU cores were a very common occurrence back then. Neither of these issues exist any more with modern hardware.

If you want to play it extra safe, just be careful when transporting the system to avoid subjecting it to sudden jolts. Lay it down flat on the car seat, motherboard side down, and wedge something in front of it to keep it from sliding off the seat if you make a sudden stop. If it can't go on a seat, wrap it in an old blanket and lay it down in the trunk. (You really should take these precautions anyway, since the hard drive is sensitive to mechanical shock.)

Several years ago I had a dual Socket A system; I put some monster copper coolers + 80mm low RPM case fans on both CPUs to keep the noise down. Never had a problem with the coolers... and this was back when the HSF still clipped to the socket, and AMD's CPUs still had exposed cores! (That system never got moved though; basically it spent ~4 years under my desk.)

just brew it! wrote:Never had a problem with the coolers... and this was back when the HSF still clipped to the socket, and AMD's CPUs still had exposed cores!

I still shudder at the thought of latching down a Socket A HSF. One slip of that screwdriver ...

That was one of those things that was much less intimidating after two or three dozen repetitions.

Except for a guy I knew who installed four Socket-A heatsinks in succession, not realizing he was putting too much pressure on one side of the CPUs, and killing four Athlon Thunderbird 1.4GHz in the process.

just brew it! wrote:If you want to play it extra safe, just be careful when transporting the system to avoid subjecting it to sudden jolts. Lay it down flat on the car seat, motherboard side down, and wedge something in front of it to keep it from sliding off the seat if you make a sudden stop. If it can't go on a seat, wrap it in an old blanket and lay it down in the trunk. (You really should take these precautions anyway, since the hard drive is sensitive to mechanical shock.)

JBI makes a good point. As I mentioned before, I transport my rig fairly often, and the particular configuration is always inside the box the case is in (with the original foam inserts), and usually on its side and wedged in next to something soft like some laundry. If I can't put it down on its side, I actually buckle it into a seat so it doesn't tip over, but those times are few and far between. I've read of some people (not around here, I don't think) that remove anything attached to the motherboard but the CPU and HSF and pack it with something that doesn't generate static, like a cotton blanket.

Captain Ned wrote:

just brew it! wrote:Never had a problem with the coolers... and this was back when the HSF still clipped to the socket, and AMD's CPUs still had exposed cores!

I still shudder at the thought of latching down a Socket A HSF. One slip of that screwdriver ...

I was always more concerned with slipping and sticking the screwdriver in my hand than the CPU .